An outboard motor is three assemblies stacked on top of each other: the powerhead (the engine), the midsection (the drive shaft housing and the brackets that mount it to the transom) and the lower unit (the gearcase, water pump and propeller). Everything else is a control (tiller handle or remote control box, cables, switches, gauges) or a supply (fuel tank and hose, battery and wiring). Knowing which group a part belongs to gets you to the right Suzuki OEM part number quickly and usually tells you whether it is a weekend job or a dealer job.
Every major component follows in that order, each linked to its collection in our Suzuki genuine parts catalog; figures live on the linked charts, not here.
Outside the cowling: the parts your owner's manual labels
Every Suzuki owner's manual opens with a "Location of parts" drawing; the names below are the manual's own, from the DF9.9B/15A/20A, DF25A/30A, DF40A/50A/60A, DF150A/175A/200A and DF300B/350A manuals.
| Part (manual's name) | What it does | Where to find it |
|---|---|---|
| Motor cover | The cowling: keeps spray out and feeds the engine air. | Engine covers and cowlings, cowling panels, emblems and decals |
| Clamp bracket, clamp screw | Hangs the motor on the transom. Bolt it as well: held only by the clamp screws, the manual says the motor may come off. | Engine holders and clamps; mounting guide |
| Tilt pin; tilt lock lever, tilt up lock arm | Sets the trim angle on manual-tilt DF9.9B–DF25A models; never run with it removed. The lock lever holds the motor tilted while stationary, never for trailering. | Tilt and shallow-water guide |
| Power trim and tilt (PTT) switch, PT switch; manual release screw | Runs the electric tilt motor. Backing out the release screw lets you tilt by hand: two turns counterclockwise on the DF9.9B–DF30A manuals, four on the DF40A–60A; retighten after. | PTT troubleshooting |
| Tilt limit cam | DF150A–200A and DF300B/350A: a stop you adjust if the motor contacts the motor well while tilting. | Trim and tilt parts |
| Water intake hole; pilot water hole; flush plug (Flush plug No.2 on DF150A–200A) | Cooling water enters at the screened intake slots on the gearcase, the flush plug is the garden-hose connection for flushing, and the pilot hole is the tell-tale: water should spray out as soon as the engine starts; if not, stop the engine. | Cooling and water pump parts; overheating guide; flushing guide |
| Engine oil drain plug | Drains the crankcase at an oil change. | Drain plugs and gaskets; oil capacity chart |
| Anti-cavitation plate | The plate above the propeller; it sets mounting height and blocks the propeller when you change one. | Shaft length guide |
| Trim tab (Anode); anode | The trim tab is the adjustable fin under that plate (boat veers to port: move its rear end toward port) and on the DF25A–DF60A manuals is itself an anode. Anodes are sacrificial metal that corrodes instead of the motor: replace at 2/3 gone, never paint; internal powerhead anodes are a dealer item. | Anodes and corrosion protection; anodes and trim tabs; anode guide |
| Gear oil level plug, gear oil drain plug, air vent hole plug | Gearcase fill and drain points; the DF300B/350A drawing adds a plug for the gear oil level adjustment hole and an oil changer plug. | Gear oil capacity chart |
| Fuel connector, fuel hose, priming bulb, air-vent screw | The portable-tank side. Squeeze the bulb until it resists before starting; a closed tank vent is a listed no-start cause. | Fuel hoses and lines; tank and hose fittings |
| Starter grip, starter button; caution lamp; combination emergency stop switch and normal stop button | Rope handle or electric-start button, the caution systems' warning light, and the lanyard kill switch: with its lock plate out the starter may turn but the engine cannot start. | Switches and keys; warning light and buzzer guide |
| Throttle control grip, shift lever, throttle tension adjuster, steering tension adjuster | The tiller handle's controls. | Tiller handles and kits |
| Remote control handle, lock-out lever, warm-up lever, ignition key; free accelerator button (DF40A–60A); shift lock button, throttle only switch, select switch (DF300B/350A) | The remote control box's controls. | Remote controls and binnacles |
| Monitor-tachometer, multi-function gauge, keyless FOB | Optional parts from a Suzuki dealer on the DF150A–200A. | Gauges and instruments |
Inside the powerhead
Cylinder block, head and gaskets. The block holds the cylinders and crankshaft; the head closes each cylinder and carries the valves, camshaft and plugs, and the head gasket keeps combustion, oil and cooling water apart, so a failed one shows as overheating or milky oil. Engine and powerhead parts, gaskets, seals and O-rings, engine bolts and fasteners.
Pistons, rings and cylinders. Combustion pushes the piston down; the rings seal it to the cylinder wall, and worn rings mean low compression, which a compression test measures. Pistons, rings and cylinders.
Crankshaft, connecting rods and bearings. The rods turn the pistons' stroke into rotation at the crankshaft, which runs straight down to the drive shaft on plain bearings that live on oil pressure alone. Crankshafts and connecting rods, engine bearings.
Camshaft and valve train. The camshaft opens the valves in time with the pistons; valve lash (cam-to-valve clearance) is a scheduled dealer check (valve clearance chart). On the DF9.9B/15A/20A a timing belt drives the camshaft: inspected every 200 hours (12 months), replaced every 4 years, dealer work. The DF150A–200A schedule has no belt row but a balancer chain replaced every 1600 hours. Valve train and camshafts.
Flywheel and ring gear. Smooths the crankshaft's rotation and carries the charging magnets; the ring gear around it is what the starter pinion engages. Flywheels and ring gears.
Starter motor and charging system. The starter cranks the engine; the stator under the flywheel makes current and the rectifier turns it into battery charge. Starters and charging systems; battery requirements chart.
ECM (engine control module). Times ignition and injection, runs the caution systems and stores diagnostic codes (diagnostic code page; the dealer's tool: SDS explained). ECU and engine control units.
Ignition coils and spark plugs. The coil steps battery voltage up to fire the plug. The DF9.9B–DF30A manuals list a digital CDI ignition, the DF40A–60A manual a full-transistor one; all say resistor-type plugs only (spark plug chart). Ignition coils and spark plugs, electrical and ignition parts.
Throttle body and intake. The throttle valve meters air into the intake; an IAC (idle air control) valve bypasses it to hold idle. The DF300B/350A fuse box has a throttle valve fuse because that throttle is electronic. Throttle bodies and intake.
Fuel pumps, injectors and filters. A low-pressure pump lifts fuel through the low-pressure fuel filter, an owner item (guide); a high-pressure pump feeds the injectors, and its filter on the DF150A–200A is a dealer item replaced every 1000 hours. Carbureted portables use a carburetor and have no injectors. Fuel pumps and injectors, fuel filters and separators, carburetors, fuel system parts, hose clamps and fittings.
Oil pump, oil filter and seals. The manuals call it trochoid pump pressure lubrication: the pump pushes oil through the filter to the bearings, an oil pressure switch feeds the caution system, and crankshaft seals keep the oil out of the drive shaft housing. Oil system parts, oil seals, oil filters, ECSTAR oils.
Thermostat. Holds cooling water in the block until the engine is warm, then opens. A failed thermostat heads the DF150A–200A manual's causes for a caution-system alert, and the DF150A–200A and DF300B/350A have a "Check Thermostat" alert (thermostat lookup). Thermostats and covers, all Suzuki thermostats.
Water pressure (poppet) valve. Bleeds off cooling water pressure at higher rpm; the 17660-99E01 valve covers 25 hp through 300 hp.
Exhaust. Leaves the head through a water-jacketed passage and exits through the propeller hub, which is why laying a motor the wrong way can put water into a cylinder through the exhaust port. Exhaust components.
The midsection
Drive shaft housing. The casting between powerhead and gearcase; the drive shaft runs down the middle, exhaust and cooling water through passages around it. Drive shafts and housings.
Engine holder, mounts and swivel bracket. The powerhead bolts to the engine holder; rubber mounts between it and the swivel bracket absorb vibration, and the swivel bracket pivots for steering and tilts in the clamp bracket. Grease the nipples with marine-grade water resistant grease such as ECSTAR EP2, never with a powered grease gun. Swivel brackets and mounts.
Tilt and power trim and tilt. Manual-tilt motors use the tilt pin and a lock lever or arm; PTT motors use an electric motor, pump and rams, with the manual release screw for tilting by hand. PTT motors and assemblies.
Steering bracket and drag link. The arm the tiller or steering cable attaches to; a drag link ties it to remote steering. The DF150A–200A manual says to lock the motor fully tilted up before greasing its nipple. Steering brackets and hardware.
The lower unit
Water pump and impeller. A rubber impeller on top of the gearcase, turned by the drive shaft; its vanes wear and take a set, which is why the pilot hole goes dry before anything else fails. Interval: impeller interval guide; the job: impeller and thermostat replacement. Water pump kits and impellers, water pump repair kits.
Drive shaft, pinion gear and gear set. The pinion on the bottom of the drive shaft turns the drive from vertical to horizontal through the forward and reverse gears on the propeller shaft; a damaged drive shaft, propeller shaft or propeller bush is what the DF150A–200A manual lists when the propeller will not turn. Gear sets and pinion gears.
Clutch dog and shift rod. The shift rod slides the clutch dog along the propeller shaft to lock it to forward or reverse gear; a worn dog makes a lower unit jump out of gear. Lower unit and gearcase parts.
Propeller shaft. Carries the propeller through the rear bearing carrier; fishing line behind the prop cuts its seal. Propeller shafts and components.
Bearings, seals and shims. Seals keep gear oil in and water out; milky gear oil, which the manual flags as contaminated, usually means a seal is leaking. Shims set gear mesh on a rebuild. Lower unit bearings and seals, shims and spacers.
Gearcase and complete lower units. Often cheaper than rebuilding a cracked housing or stripped gears; we stock them for the DF9.9B/15A/20A and DF25A/30A (special order, non-returnable). Lower unit assemblies, complete lower units.
Propeller and hardware. Stopper, propeller, nut and the cotter pin that locks it, on greased splines; the stack varies by model, so follow your manual. Sizes: propeller chart; choosing pitch: full-throttle rpm guide. Propellers and prop parts, genuine propellers, propeller hardware.
Controls, rigging and the parts on the boat
Tiller handle. Throttle grip, shift lever, stop switch and, on power-tilt models, the PT switch in one arm. Converting a DF9.9B/15A/20A to remote: tiller-to-remote guide.
Remote control box and binnacle. Side-mount or top-mount; mechanical boxes move throttle and shift cables, Suzuki Precision Control boxes send electronic signals instead (drive-by-wire explained). Controls and steering parts.
Throttle and shift cables. Push-pull cables from the box to the engine's throttle and clutch levers; measure before ordering (how to measure control cables). Throttle and shift cables.
Switches, keys and keyless start. Ignition, engine and emergency stop switch panels and the keyless FOB are optional parts on the DF150A–200A. Conventional key switches take the 37141-98LA0 key; keyless models: keyless start and emergency passcode.
Wiring harness, fuses and battery cables. The main harness links the ECM, switches and gauges to the engine, the fuse box protects each circuit, and bonding wires tie the engine components to a common ground so the anodes protect all of them. Wiring harnesses and cables, fuses, bulbs and electrical accessories; fuse chart; battery cable guide.
Rigging. Kits, their fasteners and finishing accessories. Rigging kits and installation, rigging hardware and fasteners, rigging and accessories.
The parts you replace on a schedule
The maintenance chart runs by hours or months, whichever comes first, and marks dealer items with an asterisk, explained on the maintenance schedule page; the maintenance kit lookup gives the kit for your model.
- Engine oil and filter: the DF9.9B/15A/20A manual replaces the filter at the initial 20 hours (1 month) and every 200 hours (12 months). Oil change kits.
- Gear oil: ECSTAR gear oil.
- Spark plugs: NGK plugs by model.
- Low-pressure fuel filter: inspected at the initial 20 hours and every 100 hours, replaced every 400 hours (2 years) on the DF9.9B/15A/20A and DF150A–200A manuals; water-separating filter element every 12 months. Fuel filters.
- Water pump impeller and thermostat: dealer inspection items on the schedule. Water pump repair kit by model.
- Anodes: replaced at 2/3 gone.
- Timing belt, balancer chain and high-pressure fuel filter: dealer items at the intervals above.
Bundles: service and maintenance kits, all maintenance kits.
How to find the right Suzuki part number
Have the model code and serial number from the motor's ID plate ready; we will confirm fitment from them if you are not sure. Suffixes in our listings: S short shaft, L long, X extra-long, E electric start, T power trim and tilt (power tilt on the DF9.9B/15A/20A) with remote control, TH power trim and tilt with tiller, W white.
Then browse the complete Suzuki OEM catalog or the collections above. Special tools, from the compression tester attachment to the oil pressure gauge, are in service tools. Dealer-assigned work may be a warranty matter; check with your dealer first.
Parts for this job. Start with outboard parts and accessories or Suzuki engine maintenance; the collections above cover everything from a head gasket to a cotter pin, and our Suzuki outboards run up to 30 hp. We are an authorized Suzuki, Honda and Yamaha dealer; orders over $149 ship free to the lower 48.
Sources: Suzuki owner's manuals for DF9.9B/15A/20A (2020), DF25A/30A (2019), DF40A/50A/60A (2022–2024), DF150A/175A/200A (2023–2024) and DF300B/350A (2023); Boat Max Online catalog records for part numbers and model codes. Figures are Suzuki's published values; confirm against the manual for your model year and serial number.